Paper sheet handling apparatus

Abstract

Two thickness detectors (5) each for outputting an electric signal representing the thickness of a paper sheet (B) passing thereby are arranged side by side in the width direction of a paper sheet conveyance path (3). Parameters such as paper sheet thickness, length, the existence of skew and, if skew exists, the skew angle (θ), are calculated based on the output signals from the thickness detectors. This facilitates detection of two or more overlapping bank notes among a wide variety of bank notes having different thicknesses or in case of a bank note having a significantly non-uniform thickness. The correct thickness of a paper sheet is also obtained at all times by using the skew angle and the reference length (W) of the paper sheet. This not only facilitates detection of two overlapping bank notes among a wide variety of bank notes having different thicknesses or in case of a bank note having a significantly non-uniform thickness, but also enables detection to be made very accurately. The number of paper sheets being conveyed past the thickness detectors at one time is determined based on the output signals of the thickness sensors. If the number of sheets has been reliably determined, this number of sheets is released even when sheets are being conveyed in an overlapping state and not just singly.

What is claimed is: 
     
       1. A paper sheet handling apparatus comprising: at least two thickness detectors arranged spaced apart with a spacing therebetween in a direction perpendicular to a conveyance path along which paper sheets are conveyed, said spacing being adapted to be slightly less than a width of a paper sheet, each of said thickness detectors including a respective displacement sensor for providing an analog electrical output signal having an amplitude representing a thickness of said paper sheet conveyed along said path;   means for measuring a time difference between leading edges of the analog output signals from the two displacement sensors and detecting a skew angle of a paper sheet conveyed along said path by using the measured time difference;   means for integrating the output signal from at least one of said two displacement sensors over a period of time required for the paper sheet to pass by said thickness detectors;   arithmetic means for calculating the thickness of the paper sheet from the detected skew angle, the integrated value and a reference length of said paper sheets in a direction longitudinal of said conveyance path of the paper sheets.   
     
     
       2. An apparatus for detecting parameters of paper sheets, comprising: at least two thickness detectors arranged spaced apart with a spacing therebetween in a direction perpendicular to a conveyance path along which paper sheets are conveyed, said spacing being adapted to be slightly less than a width of a paper sheet; and   arithmetic means for calculating parameters of paper sheets conveyed along said path based on output signals produced by said thickness detectors, said parameters including information relating to a skew of a paper sheet conveyed between said detectors;   each of said thickness detectors comprising:   a receiving member provided on one side of the conveyance path of the paper sheets;   a detecting roller provided opposite said receiving member on the other side of the conveyance path and urged in a direction to contact said receiving member, said detecting roller being free to move toward and away from said receiving member; and   a displacement sensor for outputting an electric analog output signal representing an amount of displacement of said detecting roller displaced by a paper sheet conveyed along said path between said receiving member and said detecting roller, said displacement sensor including a light projector and a light receiver for receiving at least a portion of the light projected from the light projector, an amount of said light received by said light receiver varying in accordance with said amount of displacement of said detecting roller, and an amplitude of said electric analog output signal being based on said amount of light received by said light receiver.   
     
     
       3. The apparatus according to claim 2, wherein said detecting roller is freely rotatably provided substantially midway along a detecting lever pivoted at one end and biased by a spring, and said displacement sensor is arranged so as to detect a magnified amount of displacement of another end of said detecting lever. 
     
     
       4. The apparatus according to claim 2, wherein said receiving member is a freely rotatable roller. 
     
     
       5. The apparatus according to claim 2, wherein parameters of paper sheets are skew angle, length and thickness. 
     
     
       6. The apparatus according to claim 2, further comprising means for integrating the electric signal outputted by said displacement sensor. 
     
     
       7. The apparatus according to claim 2, further comprising means for detecting a leading edge and a trailing edge of the electric signal outputted by said displacement sensor. 
     
     
       8. The apparatus according to claim 2, further comprising: means for integrating the electric signal outputted by said displacement sensor;   means for keeping time from a leading edge of the electric signal outputted by said displacement means to a trailing edge corresponding to said leading edge; and   means for detecting thickness of a paper sheet by dividing an integrated value provided by said integrating means by a total sum of the time provided by said timekeeping means.   
     
     
       9. The apparatus according to claim 2, further comprising: means for detecting leading edges of electric signals outputted by both of said displacement sensors;   means for keeping time from a leading edge of the electric signal outputted by one of said displacement sensors to a leading edge of the electric signal outputted by the other of said displacement sensors; and   means for detecting a skew angle using the time kept by said timekeeping means.   
     
     
       10. The apparatus according to claim 9, further comprising: means for keeping time from the leading edge to a corresponding trailing edge of the electric signal outputted by one of said displacement sensors, and   means for calculating length of a paper sheet by using the time kept by said timekeeping means and the skew angle calculated by said skew angle detecting means.   
     
     
       11. A paper sheet releasing apparatus comprising: at least two thickness detectors arranged spaced apart with a spacing therebetween in a direction perpendicular to a conveyance path along which paper sheets are conveyed, said spacing being adapted to be slightly less than a width of a paper sheet, each of said thickness detectors providing an analog electrical output signal having an amplitude representing a thickness of said paper sheet conveyed along said path,   wherein each of said thickness detectors comprises: a receiving member provided on one side of the conveyance path of the paper sheets;   a detecting roller provided opposite said receiving member on the other side of the conveyance path and urged in a direction to contact said receiving member, said detecting roller being free to move toward and away from said receiving member, said detecting roller being freely rotatable and provided substantially midway along a detecting lever pivoted at one end and biased by a spring; and   a displacement sensor for outputting an electric signal representing an amount of displacement of said detecting roller displaced by a paper sheet conveyed between said receiving member and said detecting roller, wherein said displacement sensor is arranged so as to detect a magnified amount of displacement of another end of said detecting lever; and     means for calculating the number of paper sheets conveyed along said path based on output signals produced by the displacement sensors of said thickness detectors; and   means for counting the calculated number of paper sheets as a number of paper sheets which have been released.   
     
     
       12. A paper sheet releasing apparatus comprising: at least two thickness detectors arranged spaced apart with a spacing therebetween in a direction perpendicular to a conveyance path along which paper sheets are conveyed, said spacing being adapted to be slightly less than a width of a paper sheet, each of said thickness detectors including a respective displacement sensor for providing an analog electrical output signal having an amplitude representing a thickness of a said paper sheet conveyed along said path;   means for calculating the number of paper sheets conveyed along said path based on output signals produced by said displacement sensors, wherein said paper sheet number calculating means comprises: means for detecting leading and trailing edges of the output signals of said displacement sensors; and   first means for counting the detected leading and   second means for counting the calculated number of paper sheets as a number of paper sheets which have been released.     
     
     
       13. A paper sheet releasing apparatus comprising: at least two thickness detectors arranged spaced apart with a spacing therebetween in a direction perpendicular to a conveyance path along which paper sheets are conveyed, said spacing being adapted to be slightly less than a width of a paper sheet, each of said thickness detectors including a respective displacement sensor for providing an analog electrical output signal having an amplitude representing a thickness of said paper sheet conveyed along said path;   means for calculating the number of paper sheets conveyed along said path based on output signals produced by said displacement sensors,   wherein said paper sheet number calculating means comprises: means for integrating the electric signal outputted by at least one of said displacement sensors to produce an integrated value;   means for keeping time from a leading edge of the electric signal outputted by said at least one displacement sensor to a trailing edge following said leading edge;   means for detecting the thickness of a paper sheet by dividing the integrated value provided by said integrating means by a total sum of the time provided by said timekeeping means; and   means for determining a number of paper sheets by comparing the detected thickness with a given reference value; and     means for counting the calculated number of paper sheets as a number of paper sheets which have been released.   
     
     
       14. An apparatus for detecting the thickness of paper sheets, comprising: at least two thickness detectors arranged spaced apart with a spacing therebetween in a direction perpendicular to a conveyance path along which paper sheets are conveyed, said spacing being adapted to be slightly less than a width of a paper sheet;   means for measuring a time difference between leading edges of output signals from the two thickness detectors and detecting a skew angle of a paper sheet conveyed along said path by using the measured time difference;   means for integrating the output signal from at least one of said two thickness detectors over a period of time required for the paper sheet to pass by said thickness detectors; and   arithmetic means for calculating the thickness of the paper sheet from the detected skew angle, the integrated value and a reference length in a direction longitudinal of said conveyance path of the paper sheets.   
     
     
       15. The apparatus according to claim 14, wherein each of said thickness detectors comprises: a receiving member provided on one side of the conveyance path of the paper sheets;   a detecting roller provided opposite said receiving member on other side of the conveyance path and urged in a direction to contact said receiving member, said detecting roller being free to move toward and away from said receiving member; and   a displacement sensor for outputting an electric signal representing an amount of displacement of said detecting roller displaced by a paper sheet conveyed between said receiving member and said detecting roller.   
     
     
       16. The apparatus according to claim 15, wherein said detecting roller is freely rotatably provided substantially midway along a detecting lever pivoted at one end and biased by a spring, and said displacement sensor is arranged so as to detect a magnified amount of displacement of another end of said detecting lever. 
     
     
       17. The apparatus according to claim 15, wherein said receiving member is a freely rotatable roller. 
     
     
       18. A paper sheet handling apparatus comprising: at least two thickness detectors arranged spaced apart with a spacing therebetween in a direction perpendicular to a conveyance path along which paper sheets are conveyed, said spacing being adapted to be slightly less than a width of a paper sheet;   each of said thickness detectors including a respective displacement sensor for providing an electric analog signal representing an amount of displacement caused by a paper sheet conveyed along said path;   skew determining means connected to the displacement sensors for determining a skew angle of a paper sheet conveyed along said path between said detectors based on a time difference between predetermined edges of the output signals from said two displacement sensors.   
     
     
       19. A paper sheet handling apparatus comprising: at least two thickness detectors arranged spaced apart with a spacing therebetween in a direction perpendicular to a conveyance path along which paper sheets are conveyed, said spacing being adapted to be slightly less than a width of a paper sheet;   a displacement sensor in each of said thickness detectors for providing an electric analog signal representing an amount of displacement of each of said thickness detectors displaced by said paper sheet conveyed along said path;   skew determining means for determining a skew angle of a paper sheet conveyed along said path between said detectors, said skew determining means further comprising: timing means for providing a timing signal based on predetermined edges of said output signals from said displacement sensors; detecting means for detecting a skew angle of said conveyed paper sheet based on a time difference between said leading edges of said output signals; and determining means for determining said skew angle by using said measured time difference; and   means for comparing said skew angle with a predetermined upper-limit angle.